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Re: Fuel pump?
Posted: 06 May 2025, 17:42
by Smiffo
If you take the top off the carb, you will just have the bowl with the float in - won’t help you much yet.
( And if you have no spare gasket to go on, you might tear yours up a bit making it prone to air leaks )
When using fuel into the mouth of the carb, you left the black plastic off too I assume?
Re: Fuel pump?
Posted: 06 May 2025, 17:47
by Welshclimber
Yeah left the black plastic off when putting fuel in to the carb
Re: Fuel pump?
Posted: 06 May 2025, 18:03
by Smiffo
If it starts on easy start, and fuel is deffo good, I’m stumped.
I’d lean toward carb rebuild kit if it weren’t for the fact adding fuel directly in doesn’t make it fire.
This is a great vid to rebuild it, but see if anyone else spots something I’m missing before you go into that:
Re: Fuel pump?
Posted: 06 May 2025, 20:08
by Welshclimber
So I went back out tonight to check because I couldn’t remember if I tried putting the fuel in before or after changing the spark plugs. So turns out that it is starting to catch with putting fuel straight in to the carb. The fuel pump is working so this would mean it’s between the fuel pump and the chamber that the fuel goes in to. Is the carb refurb kit the only option here? Just to make sure I’ve ruled everything else out
Re: Fuel pump?
Posted: 06 May 2025, 20:19
by Smiffo
Ok, so there is a cut off valve on the carb that stop fuel filling the bowl when you turn ignition off.
There will be a black ( on mine ) wire going to the carb that needs 12v on it to keep valve open.
Check you have voltage on that with ignition on. Skip to 37:20 mins in the second video I posted above to see what I mean.
Re: Fuel pump?
Posted: 06 May 2025, 20:32
by Smiffo
Also, you can check fuel filter which is at 4 mins in the first video
Re: Fuel pump?
Posted: 08 May 2025, 18:40
by Welshclimber
Thanks Smiffo, checked the little filter today and that’s clear, sprayed some carb cleaner in the top and it started but then died. Checked the fuel coming out of the pump and it’s milky, so looks like we have water in the fuel.
Checked the filler neck and can’t see any splits, I’m assuming that the next culprit would be the tank itself?
Re: Fuel pump?
Posted: 08 May 2025, 18:48
by Smiffo
Yeh, those tanks are minging to get off too.
There are plenty of rubber grommets and breather hoses that can perish, plus the tanks have a ’nice’ bowl shape on the top that seems to collect years of grime and they rot through. Could be any of the above, or all if it hasn’t been changed before.
Drop the tank and assess from there I suppose. The good news is Brickwerks do all the bits you need.
( I used them when I did my tank )
Re: Fuel pump?
Posted: 09 May 2025, 08:29
by Stesaw
I'm just jumping in here so sorry if this has been mentioned. Have you checked to make sure the fuel cutoff solenoid on the carb is working when then ignition is On? Should make an audible click when the ignition is switched on.
Re: Fuel pump?
Posted: 15 May 2025, 21:42
by Welshclimber
So the story continues ha. Rather than dropping the tank, I drained off the water from the bottom of the tank, then put a bottle of the wynns stuff that emulsifies water to get rid of the rest. Since draining the water off it idles completely fine. Also changed the fuel filter, and the fuel seems to sit quite low in this, is that normal for it not to reach the pipe level? Took it for a run and im losing power at low revs, particularly downhill where it cuts out completely, feels like it’s not getting enough fuel?
Re: Fuel pump?
Posted: 15 May 2025, 21:43
by Welshclimber
And yeah checked the solenoid it’s working fine
Re: Fuel pump?
Posted: 15 May 2025, 22:24
by tobydog
Water and crap in carb plus idle jet bunged up??? I'd clean the carb out for peace of mind.

Re: Fuel pump?
Posted: 15 May 2025, 22:53
by Welshclimber
Thanks, is it best to get the new gaskets for this and do the full clean and service of it? Is there a quick way to clean out to get me to a festival the end of the month??

Re: Fuel pump?
Posted: 24 May 2025, 15:17
by Welshclimber
Any further help on this appreciated…
I bought the carb service kit from Brickwerks, followed the two videos above. Re-fitted the carb and it started first time! Idled for a while but it was slow so we opened up the idle speed screw a quarter turn and it ran lovely, turned the engine off and re-started fine. Then tried driving and it cut out straight away and now won’t start again. If I keep my foot in the accelerator it will keep running but dies as soon as I take it off.
Re: Fuel pump?
Posted: 24 May 2025, 18:31
by Welshclimber
Oh and to top it off I’ve got a brand new oil leak which I’ve never had before